As s substrate processing system for performing a process, such as a cleaning process, for a substrate, such as a semiconductor wafer (hereinafter referred to as “wafer”), various types of systems have been conventionally known. In such a substrate processing system, a wafer container (hereinafter referred to as “container”) such as a FOUP (Front Open Unified Pod), which accommodates a plurality of wafers arranged in a horizontal state in the up and down direction, is transferred from outside to the substrate processing system. Then, the plurality of unprocessed wafers are collectively brought out from the container and sent to a Processing part of the substrate processing system. Thereafter, the plurality of wafers are subjected to a process such as a cleaning process by a batch method. Following thereto, the plurality of processed wafers are collectively transferred from the processing part to the vacant container, and the plurality of processed wafers are brought into the container.
Before the unprocessed wafers are brought out from the container, and after the processed wafers are brought into the container, the wafers in the container are detected. To be specific, the number of the wafers accommodated in the container is detected and/or whether the respective wafers are normally accommodated in the container is detected. As such a detecting apparatus for detecting wafers in a container, the invention disclosed in JP2009-65212A has been known.
In a conventional substrate processing system, a common detecting apparatus is used both before unprocessed wafers are brought out from a container and after processed wafers are brought into the container. In addition, when wafers accommodated in the container are detected, the detecting apparatus used in the conventional substrate processing system is adapted to detect whether the wafers are respectively accommodated in respective accommodating portions of the container or not, and to detect accommodated conditions of the respective wafers accommodated in the respective accommodating portions. This is because, when the container accommodating unprocessed wafers is transferred from outside to the substrate processing system, there is a case where some wafers are not normally accommodated in the container. In this case, when the wafer that are not normally accommodated in the container is brought out therefrom, various troubles may occur in the subsequent processing steps for the wafers.
On the other hand, when the processed wafers are returned from the processing part to the container, the wafers are normally brought into the container in general. Thus, when the processed wafers in the container are detected after the wafers have been brought into the container, it is sufficient to detect only the number of the wafers accommodated therein. However, as described above, since the same detecting apparatus is used both before the unprocessed wafers are brought out from the container and the processed wafers are brought into the container, the accommodated conditions of the respective processed wafers accommodated in the respective accommodating portions of the container (whether the wafers are normally accommodated or not) is also detected, even when the processed wafers accommodated in the container are detected. Thus, a time period required for detecting the wafers is prolonged.
The present invention has been made in view of the above circumstances. The object of the present invention is to provide a substrate processing system, a substrate detecting apparatus, and a substrate detecting method, which are advantageous in the following points. Namely, when substrates accommodated in a container are detected, since substrates in an unprocessed condition and substrates in a processed condition are detected by detecting parts that are different from each other, a detection result needed for the substrates in the respective conditions can be appropriately obtained. Further, a detection period for the substrates can be reduced, as compared with a single detecting part which detects both unprocessed substrates and processed substrates. Thus, a throughput of a process of the substrates can be improved.